Stop mechanism



April 25, 1944. H. A. SIMMONDS EI'AL STOP MECHANISM Filed April 14, 1943 [PA 3 MM 4, w N f HMVW A\. Q 1E7 Q m A0 7 HEM m 3 H m v F, v K H A 7 Patented Apr. 25, 1944 STOB MECHANISM Harold A. Simmonds and Edward M. Mcllvaine,

United States Navy Application April 14, 1943, Serial No. 482,960

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4 Claims.

The present invention pertains to a safety attachment for tape feeding mechanisms and may be used to shut off any tape feeding device whenever the tape becomes twisted or tangled in order to prevent tearing thereof by entering the tape guide of the device in a deranged condition. It is adaptable primarily for use on transmitters used in teletype machines, Where a tape is perforated in a perforating machine and is then fed into a transmitting device where the perforations are translated into electric signals for transmission to and reproduction at some remote point.

The object of this attachment is to permit continuous operation of a transmitting device to which a tape is fed so long as the tape approaches the device in a normal condition but as soon as a twist or tangled portion of the tape reaches this attachment it immediately draws the attachment into operation to shut off the transmitting device. According to the preferred embodiment of this invention as applied to teletyping transmitters it is contemplated to connect the attachment to the control switch of the motor which drives the transmitter and places it in a position adjacent the point where the tape enters the transmitter in such a manner that the tape' has to pass through a space between two strips of the safety attachment and in such a manner that the shut-off movement of the safety device, in the direction towards said point of entry of the tape into the transmitter device, will operate the control arm of the motor control to shut the motor off.

A better understanding of this invention may be had from the following description taken in conjunction with the accompanying drawing wherein:

Fig. 1 is a perspective view of a transmitting device showing a portion of the motor casing attached thereto and the end of a control arm for said motor having the device of the present invention attached thereto.

Fig. 2 is a plan view on an enlarged scale of the safety attachment, and

Fig. 3 is a side view thereof.

Referring more particularly to the drawing, in Fig. 1, the tape I is fed to the transmitter 2 through the tape guide 3. The shut off bar 4 which is attached to the control switch for controlling the motor 5 which operates the transmitter has connected to its end the safety attachment 6, which is composed of two strips, 1 and 8, fastened together with a narrow space therebetween by means of the post assembly 9 which connects the attachment to the shut off bar by means of set screw It). The post assembly is made up of sleeve ll having a threaded bore therethrough and a cross bore [2 which slides over the shut off bar. A set screw l3 fitting into the threaded bore from one end serves to lock the post assembly on the shut off bar at the desired point and in the desired position. Another screw l4 fits into the other end of the post after being passed through openings in the ends of the strips 1 and 8 with a washer I5 between them for the purpose of fastening these strips in proper position on the post assembly. The shut off bar works in a vertical plane, in this instance, about the switch pivot on the motor.

Considerable trouble has been experienced with teletypewriters using automatic transmitting devices when the transmitting tape becomes fouled. These teletypewriters normally have a shut off bar on the transmitter motor the arm of which is positioned across the tape between the perforator and the transmitter so as to shut off the motor whenever the tape is pulled taut between the perforator and the transmitter to shut the motor off and stop the transmitter whenever there is a lack of sufficient tape already perforated by the perforator. There is, however, no means for preventing the feeding of twisted tape to the transmitter and at times when there is an excessive accumulation of tape between the perforator and transmitter the tape may get tangled at this point. When the tangled portion reaches the transmitter guide or even should it pass the guide and reach the stepping mechanism of the transmitter it would get torn or injured to the extent that transmission would be interrupted and considerable delay would be effected before the operation could be resumed.

By-the use of this simple attachment it has been found that considerable saving of time and effort may be made and the above difficulties overcome. The narrow slot in the attachment will not permit the passage of fouled tape. The fouled tape will be either straightened out and fed to the transmitter correctly or will be caught in the slot and the shut off bar will be thereby operated to its shut off position and the transmitter shut off before the tape can be injured.

Although this device has been described in connection with its use on a teletypewriting machine it may be used on any other tape feeding device where the tape is subject to possible twisting or tangling before reaching the feeding device. The form of the device described may be modified in size and shape to meet the many specific requirements.

This invention may be used by or for the Government of the United States of America for governmentaI purposes without the payment to us of any royalties thereon or therefor.

Whatwe claim is:

1. In an automatic tape feeding mechanism driven by a motor, a shut-off means for said motor, an attachment on said means having a pair of strips fitting loosely over the tape being fed, said attachment being adapted to-be drawn by the tape in the tape feeding direction to operate said shut-off means whenever the tape is twisted so that it will not straighten out as it is pulled through the strips, thus preventing tearing of the tape or stripping of its feeding perforations.

2. A safety attachment for connection to a shut off bar on a motor driving a tape feeding mechanism, composed of a pair of strips, between Which the tape is loosely fed, mounted at one end on a post which is adjustably fastened to the shut off bar so as to position the strips in such a manner that they will move the shut 01f bar into the shut off position when moved in the l able thereon, a pair of strips spacedly mounted on said post to form a narrow slot through which the tape is passed, the shut-oiT movement of the bar being in the direction of the movement of the tape during operation by an accidental knot or twist in the tape that will not straighten out. 4. In a safety attachment for a positive gear tape-feeding mechanism driven by a motor having a shut off bar, a post assembly including a threaded sleeve having at one end a cross bore fitting over the shut-off bar and a set screw for fixing the assembly on the bar, a strip positioned on each side "of the tape being fed to the mechanism at a point on the tape spaced from the mechanism, the corresponding ends of said strips being fastened by a screw to the other end of said post assembly.

HAROLD A. SIMMONDS, EDWARD M. MCILVAINE. 

